A coordinated multidisciplinary program for the evaluation of the events which occur in the early stages of reproduction, ranging from sperm physiology to preimplantation ovum development is proposed. Broad areas covered encompass sperm metabolism, ovarian function and the intraluminal conditions in the female reproductive tract. Specific projects include investigation of metabolic a membrane bioenergetics in spermatozoa (Storey and Chance), endocrine control of ovarian and reprodutive tract functions (Mikhail, Flickinger), acrosomal enzymes and their role in fertilization (Stambaugh), and the oviductal and uterine environments and their regulation (Mastroianni, Seitz). Supporting facilities include an Endocrine laboratory for hormone assays, and a monkey colony. BIBLIOGRAPHIC REFERENCES: Mastroianni, L., Jr., and Brackett, B.G. Intraluminal tubal environment. Chapter in: Progress in infertility. 2 ed. S.J. Behrman andR.W. Kistner, eds. Boston: Little, Brown. 1975. pp. 175-88. Mastroianni, L., Jr., and Komins, J. Capacitation, ovum maturation, fertilization and preimplantation development in the oviduct. Gynecol invest 6:226-33, 1975.